In the event that several trade unions or other representations authorized by workers participate simultaneously on behalf of these workers, a representative common body will be created for the conduct of negotiations, the development of a single draft text and the conclusion of a single collective agreement. This chapter presents the granularity, diversity and complexity of national collective bargaining systems in OECD countries. The analysis confirms the need to go beyond the usual macroeconomic indicators of collective bargaining: standard indicators of hedging, trade union density or centralisation mask a wide variation in collective bargaining systems. Law 24901 of the Russian Federation in compliance with collective agreements and collective agreements. March 11, 1992. (Vedomosti S`ezda narodnykh deputatov Rossijskoj federacii i werkhovnogo soveta Rossijskoj federacii, 23 April 1992, No 17, text 890, p. 1211219) Firstly, the representativeness of trade unions and employers` organisations, as measured by the proportion of employees (companies) who are members of trade unions (management organisations), as well as the proportion of workers covered by collective agreements, are key indicators of the strength of social partners and the volume of collective bargaining systems. But they are not enough on their own: the rules for the administrative extension of collective agreements beyond the signatory parties and the frequency of use of these extensions are also decisive determinants for the coverage of collective agreements. The situation is different in the public sector, where, since 1997, legislation has had the right to negotiate.  This is very similar to the rules that have now been agreed with the INPS and requires a 5% representation to participate in the negotiations, and the support of the unions with a combined representation rating of 51% for an agreement to be valid.
The value is calculated as the average of union membership and assistance in workplace elections. In summary, in Portugal, as in most other countries, it is far from easy to make clear estimates of effective wage setting. The use only of data on flows (new agreements) is not correct, as this would have the effect of ignoring workers still covered by old agreements. At the same time, the use of inventory data is also problematic, as in some cases agreements may no longer be binding or partially binding, leading to an overestimation of coverage. Changes in the average duration of agreements and possible retroactive agreements make estimating even more difficult. In addition, the choice of denominator is also essential in the calculation, particularly given the widespread use of atypical forms of employment, which are systematically not well covered by standard surveys. As a transitional solution, opening clauses were introduced in Germany in more general agreements42, which were initially limited to working time, and then extended to wages from 1995 onset, Heinbach and Maier, 2011). At first, only the unions were able to agree on a revision of the contractual terms, but collective agreements quickly allowed „employment and competitiveness pacts“ (PECs) with the works councils (with or without the formal participation of a trade union). These have spread more and more and are used independently of the specific economic situation (Seifert and Massa-Wirth, 2005). Kohaut and Schnabel (2006) indicate, based on data from the IAB`s business panel, that in 2005, 13% of companies and 29% of employees in Germany were covered by a collective agreement with an opening clause. About half of the companies concerned (53% in the west, 50% in the east) had used such a clause, mainly to change working hours, and only a third to change the base salary or annual bonuses. Data from the WSI Works Council survey (Schulten and Bispinck, 2014) and the IAB`s business panel (Addison, 2016) do not yet show any particular developments, other than a catch-up period during the crisis.